Streptomyces Growth Capacity in the Presence of Boron

NORMA B. MORAGA; MARÍA J. AMOROSO; VERÓNICA B. RAJAL

Puerto Vallarta

Simposio; 16th Internacional Symposium on the Biology of Actinomycetes.; 2011

´Boron environmental pollution in Salta state is mainly due to aggressive mining exploitation and boron compound processing, which provide great revenue profits to the state. One likely system to solve B soil contamination increasingly under study is that of bioremediation through bacteria able to grow and eliminate boron or its derivatives. Few species are mentioned in literature. Ahmed et al. (2007) and Miwa et al (2008) isolated some bacteria from naturally boron contaminated soils in Hisarcik, Turkey, requiring boron to grow or to hold high boron concentrations or even accumulate high boronic acid concentrations inside, but so far no conclusive results have been published as to the gender of the Streptomyces. In former reserches, the study area was determined, soil sampling was conducted and microorganisms were isolated from an anthropic zone (Baradero) and a naturally contaminated area (Tincalayu) in Salta state, Argentina. Out of the 127 microorganisms initially isolated, 59 were identified according to the colony morphologic features applying different tinting and chemical taxonomic tests using API 20 NE. Out of 17 Gram positive isolates, eight belong to the actinobacteria group, according to molecular identification by 16S ADNr. Boronic acid qualitative and quantitative tolerance studies were continued with the eight action bacteria strands selected on the basis of their abundance in the soils under study, their metabolic versatility and mainily, non-pathogenic. These strands selected from boron contaminated soils were sequenced and identified at molecular level and their sequences were added to the GenBank. Their growth dynamics is currently being studied in minimal fluid medium with different boronic acid concentrations and tolerance at different boronic acid concentrations (20, 40 and 80 mM) of Streptomyces achromogenes, iakyrus (Baradero) and Streptomyces sp. (Animana) has been obtained.